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Yang S.,Beijing Normal University | Yin G.,Beijing Normal University | Shi X.,National Marine Hazard Mitigation Service | Liu H.,Beijing Transportation Information Center | Zou Y.,Beijing Municipal Commission of Transport
International Journal of Disaster Risk Science | Year: 2016

Cities are centers of socioeconomic activities, and transport networks carry cargoes and passengers from one city to another. However, transport networks are influenced by meteorological hazards, such as rainstorms, hurricanes, and fog. Adverse weather impacts can easily spread over a network. Existing models evaluating such impacts usually neglect the transdisciplinary nature of approaches for dealing with this problem. In this article, a mesoscopic mathematical model is proposed to quantitatively assess the adverse impact of rainstorms on a regional transport network in northern China by measuring the reduction in traffic volume. The model considers four factors: direct and secondary impacts of rainstorms, interdependency between network components, and recovery abilities of cities. We selected the Beijing-Tianjin-Hebei region as the case study area to verify our model. Socioeconomic, precipitation, and traffic volume data in this area were used for model calibration and validation. The case study highlights the potential of the proposed model for rapid disaster loss assessment and risk reduction planning. © 2016, The Author(s).


Li F.,Chinese Research Institute of Highway | Zhou Y.,Beijing Municipal Commission of Transport | Li T.,Chinese Research Institute of Highway | Zeng W.,Chinese Research Institute of Highway | Wang X.,No. 56 Oxygen Road
International Journal of Pavement Research and Technology | Year: 2015

Low temperature performance of hot-applied bituminous crack sealant is a key factor which influences the effect of asphalt pavement crack filling and sealing. In order to describe the constitutive stress-strain relationship at low temperature, experimental tests of extension and stress relaxation of crack sealants, are presented in this paper. The generalized Maxwell model is chosen for curve-fitting to determine the material model. Comparison of fitted curve and experimental results proves that the generalized Maxwell model in Prony series is well suited for describing the experiment process. Moreover, finite element analysis method with material model defined by the generalized Maxwell model in Prony series is introduced for numerical solution of tension and stress-relaxation of crack sealants. By comparing the results of the numerical analysis and the tests, the conclusion can be made that the tension and the stress-relaxation of crack sealants may be accurately depicted by the generalized Maxwell model. © Chinese Society of Pavement Engineering.


BEIJING, Nov 2, 2016 /PRNewswire/ -- With environmental pollution as a typical issue worldwide, China, now the largest developing country in the world, has introduced several powerful measures to address the challenge of air pollution. The measures include a plan of promoting the use of electric taxis, to reduce exhaust pollution. New energy automaker BAIC BJEV, a subsidiary of Beijing Automotive Group (BAIC Group),a company that ranks 160th among the Fortune 500, has recently delivered the first few battery-switch stations for EV taxi in Beijing. So far, the stations form the largest-scale network in the world for electric taxi battery charging and swapping. The first batch of ten battery-swap stations has commenced operation on Oct. 29th and will offer services across eight urban districts in Beijing. "In 2016, 50 EV battery charging and switch stations will be put into operation in Beijing and are expected to address the battery-swap needs of at least 6,000 EV taxis. Taxi drivers will be able to remove the battery once it starts running out of power and replace it with a fully-charged one at the nearest station. The station locations have been planned so that drivers will not need to travel more than five kilometers for swapping battery. By the end of 2017, Beijing will be home to 200 EV battery charging and swapping stations, which will meet the requirements of 30,000 EVs. In preparation for the 2022 Olympic Winter Games in Beijing and Zhangjiakou, BAIC BJEV will replace 50,000 existing taxis with EVs equipped with switchable batteries," said Xu Heyi, chairman of BAIC Group. During the launch ceremony, Zhou Zhengyu, director of the Beijing Municipal Commission of Transport, said, "The control of air pollution is one of our current priorities and we are focusing on reducing pollution caused by vehicle emissions through boosting the adoption of EVs. As a forward-looking company, BAIC Group has a long track record of research and practice in the field." BAIC BJEV general manager Zheng Gang explained that as the supporting infrastructure, including the battery charging and battery switching stations, comes to maturity, the new energy automaker plans to expand its battery swapping business in the car-sharing, online car-hailing and even the private vehicle markets. He said, "We will accelerate the standardization of batteries for EVs and sharing of technologies, boost the use of the battery switching network as well as expand the related service, sharing more benefits to our partners and users in this network." As a key application in new energy technology, battery switching has always been in the industry's spotlight. Several market leaders has been exploring the commercialization of battery switching services with little success due to the difficulties in industry chains integration, huge investments needed for building stations, as well as engrained user behavior. Since 2014, BAIC BJEV has been exploring ways to efficiently promote the adoption of battery switching technology and service. Over the last two years' research and test, the company cooperated with organizations across the industry and capitalized on the favorable policies issued by the government. Today, BAIC BJEV aims to accelerate the adoption of its EV models with switchable battery and technology in cooperation with station constructors. The kick-off of this program is a milestone of the battery-switching utilization in China as well as a promising signal for its future development. To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/worlds-largest-network-of-ev-battery-charging-and-switching-stations-commences-operation-in-beijing-300355823.html


Liu X.,Beijing Municipal Commission of Transport | Chen J.,Beijing Municipal Commission of Transport | Liu Z.,Beijing Jiaotong University | Chen H.,University of Leeds | Ge Y.,Beijing Municipal Commission of Transport
Proceedings of the Conference on Traffic and Transportation Studies, ICTTS | Year: 2010

Beijing is a city with a history of about 3,000 years. In the past several decades, pursuing to be industrialized used to be a main goal of the city which caused more and more serious pollution problems. Since the late of 1990s, actions have been taken to deal with the air pollution in Beijing in order to enhance living level of its residents. However, countermeasures taken firstly were almost on the adjustment of development routine of industry. Until recent years, especially approaching the 2008 Olympic Games, complicated schemes on green transport was concretely carried out. It was not only aiming for a currently clean air, but also a future sustainable development of transport and urbanization. Among the actions taken on green transport, there are exploration of low emission vehicles, priority to public transport, cycling and walking improvement and intelligent information techniques application. This paper summarizes these action schemes and what's on now in Beijing. © 2010 ASCE.


Cheng H.,Beijing University of Technology | Yang X.-K.,Beijing University of Technology | Liu X.-M.,Beijing Municipal Commission of Transport
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2013

The purpose of traffic congestion pricing is to reassign the traffic volume for the whole road network. The problem of determining optimum toll is stated by game theory. The interaction between road authority and road users can be considered as a two-level game model with N+1 players. The two-level game model of congestion pricing is proposed and the game equilibrium is analyzed in the paper by introducing a virtual road network as an example to figure out the optimum toll. The objective of congestion pricing game is to find system-optimal tolls and user-optimal traffic flows.


Wu J.,Beijing Jiaotong University | Guo X.,Beijing Jiaotong University | Sun H.,Beijing Jiaotong University | Wang B.,Beijing Municipal Commission of Transport
Mathematical Problems in Engineering | Year: 2014

Because of the limitation of budget, in the planning of road works, increased efforts should be made on links that are more critical to the whole traffic system. Therefore, it would be helpful to model and evaluate the vulnerability and reliability of the transportation network when the network design is processing. This paper proposes a bilevel transportation network design model, in which the upper level is to minimize the performance of the network under the given budgets, while the lower level is a typical user equilibrium assignment problem. A new solution approach based on particle swarm optimization (PSO) method is presented. The topological effects on the performance of transportation networks are studied with the consideration of three typical networks, regular lattice, random graph, and small-world network. Numerical examples and simulations are presented to demonstrate the proposed model. © 2014 Jianjun Wu et al.


Cheng H.,Beijing University of Technology | Yang X.-K.,Beijing University of Technology | Liu X.-M.,Beijing Municipal Commission of Transport
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2012

In the paper, the external cost of urban expressway transportation was analyzed quantitatively by four aspects, including traffic congestion external cost, traffic accident external cost, air pollution cost and noise cost. Besides, the main road of the 3rd east ring expressway in Beijing is taken as an example to conduct the calculation of transport external cost according to different time period. In addition, the variation of transport external cost during different time periods in a day was analyzed in the paper. It was found that congestion external cost takes up the largest part of total external cost. With the increase of traffic volume and decrease of average speed, congestion external cost rises sharply.


Li D.,Beijing Jiaotong University | Zhang L.,Beijing Municipal Commission of Urban Planning | Sun Y.,Beijing Municipal Commission of Transport
Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013 | Year: 2013

Traffic surveillance systems that use cameras are an important tool for controlling pedestrian crowds in subway stations. Large stations need many cameras which cause difficulty for traffic-control operators who need to react quickly when an accident takes place at a specific location. This paper reports on a new technology based on computer vision for use in a pedestrian crowd estimation and safety detection system. The system first collects data from video cameras and instantly converts the data to gray-brightness images frame by frame. Then the outline of each pedestrian in each image is extracted using Sobel filter convolution. Parameters of the processed images are obtained for each frame. The functional relationship between pedestrian density and image parameters (such as bin30) is set up. An alert system is developed based on this proposed method. The paper presents a test-case of the Lama Temple interchange station of the Beijing subway. The density and fundamental diagram of the flow of pedestrians is tested and compared with the same data collected manually. Results show that this methodology is effective, fast, and practical for use. © 2013 IEEE.


Jin G.-H.,Beijing University of Technology | Liu X.-M.,Beijing University of Technology | Liu X.-M.,Beijing Municipal Commission of Transport | Bian Y.,Beijing University of Technology
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology | Year: 2013

Physical consumption and pedestrian flow rate are the leading influence factors in reflecting the level of service of pedestrian interchange crossing facilities. Aiming at the physical consumption of walking up and down the stairs, this paper obtains pedestrian oxygen consumption with the oxygen consumption model. It converts physical consumption into walking distance equivalently according to the equivalent relationship between the oxygen consumption. The equivalent walking distance and pedestrian flow rate threshold corresponded to each pedestrian feeling level is confirmed by two-step-cluster method combined with actual survey. Then, based on the threshold and combined with the level of service polymerization model, the evaluation on the level of service of pedestrian interchange crossing facilities can be accomplished.. As the result of this study, the following conclusions are drawn: the equivalent walking distance of the same distance up and down stairs and the actual detouring distance can make the same perception on pedestrian. The equivalent walking distance can well reflect the actual feeling of pedestrian physical consumption. The pedestrian perception from using foot-bridge and subway are respectively equivalent to 50 m and 35 m. © 2011 by Science Press.


Liu X.-M.,Beijing Municipal Commission of Transport
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology | Year: 2010

Urban transportation plays an important role in urban development. A convenient, efficient and smooth transport system is an important guarantee for sustainable urban development, and a measure of an important indicator of the level of urban modernization. Urban transport problem is the concentrated reflection of multiple conflicts in urban development. Different traffic problems can not be solved simply by applying the same mode. The paper summarizes the status of Chinese urban transport development and problems. In accordance with the concepts of humanities, science and technology, green and low carbon, urban transport development strategies are suggested for Chinese cities based on international experiences in urban transport development.

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